I am aware of the scriptural passages used to defend the divinity of Jesus Christ (Jn. 1:1; 10:30; 20:28; Col. 2:9; etc.), but what passages are there that point towards the divinity of the Holy Spirit? St. Gregory the Theologian had this to say about the apparent lack of such passages:

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To this I may compare the case of Theology except that it proceeds the reverse way. For in the case by which I have illustrated it the change is made by successive subtractions; whereas here perfection is reached by additions. For the matter stands thus. The Old Testament proclaimed the Father openly, and the Son more obscurely. The New manifested the Son, and suggested the Deity of the Spirit. Now the Spirit Himself dwells among us, and supplies us with a clearer demonstration of Himself. For it was not safe, when the Godhead of the Father was not yet acknowledged, plainly to proclaim the Son; nor when that of the Son was not yet received to burden us further (if I may use so bold an expression) with the Holy Ghost; lest perhaps people might, like men loaded with food beyond their strength, and presenting eyes as yet too weak to bear it to the sun’s light, risk the loss even of that which was within the reach of their powers; but that by gradual additions, and, as David says, Goings up, and advances and progress from glory to glory, (Ps. 84:7; 2 Cor. 3:18) the Light of the Trinity might shine upon the more illuminated." - Gregory the Theologian, Oration 31, 26

Yet even St. Gregory says that the New Testament "suggested the Deity of the Spirit". Which passages might he have been thinking of? Jn. 16:13-15 comes to mind, but what others are there?

Acts 5:3-4But Peter said: Ananias, why hath Satan tempted thy heart, that thou shouldst lie to the Holy Spirit and by fraud keep part of the price of the land? Whilst it remained, did it not remain to thee? And after it was sold, was it not in thy power? Why hast thou conceived this thing in thy heart? Thou hast not lied to men, but to God.

Good recommendation, I haven't read that since I was a catechumen, so it's been over 7 years now; I guess I owe it another reading. I've been meaning to revisit what he says about traditions/oral traditions anyway.

"Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men." - Matt. 12:31

"And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption." - Eph. 4:30

"How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God?" - Heb. 9:14

"Elect according to the foreknowledge of God the Father, through sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus Christ: Grace unto you, and peace, be multiplied." - 1 Pet. 1:2